The Collaborative International Dictionary of English v.0.48:

erysipelas \er`y*sip"e*las\ ([e^]r`[i^]*s[i^]p"[-e]*las), n.
   [L., fr. Gr. 'erysi`pelas; 'eryqro`s red + pe`lla hide, skin.
   See Red, and Pell, n.] (Med.)
   St. Anthony's fire; a febrile disease accompanied with a
   diffused red edematous inflammation of the skin, which,
   starting usually from a single point, spreads gradually over
   its surface. It is often accompanied by severe constitutional
   symptoms. It is caused by a group A hemolytic streptococcus
   (Streptococcus pyogenes), is contagious, and formerly often
   occured epidemically.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

erysipelas
    n 1: an acute streptococcal infection characterized by deep-red
         inflammation of the skin and mucous membranes